Femoral cementing techniques in total hip replacement

'linical studied have shown that second-generation femoral cementing techni ques at total hip replacement result in a superior fixation of the femoral stem. In an effort to determine what benefits further developments in cemen ting techniques would provide, we compared the morphology of the cement man tles produced by traditional finger-packing and gun-insertion techniques. T he porosity of the cement mantles was quantified using computerised image a nalysis. The finger-packing technique caused large air inclusions that resu lted in large pores in the substance of the cement mantle, whereas the ceme nt-gun technique did not result in any individual pore with an equivalent d iameter greater than 3 mm. The mean porosity of cement mantles prepared usi ng the finger-insertion technique was 8.3%, whereas the mean porosity in gu n-prepared mantles was 1.7%. The use of a cement gun significantly reduced the porosity of femoral cement mantles (P=0.02). Reduction of defects in th e substance of the cement mantle may account for the increased survival of femoral prostheses inserted when second-generation techniques were used. Fu rther reduction of the porosity of the cement mantle could not be expected to produce as dramatic a clinical improvement in prosthesis fixation.